2. Fruit Juice

Unfortunately, fruit juice isn’t always as fresh and natural as it may seem. Fruit juice can contain more sugar and calories than a sugary soft drink. According to Authority Nutrition, “After being squeezed from the fruit, the juice is usually stored in massive oxygen-depleted holding tanks for up to a year before it is packaged.” Even the highest quality juices are far from their natural state.

3. Diet Soda

“Studies have shown that drinking diet soda can actually cause a person to gain weight, have headaches and digestive problems! Instead choose seltzer water and add some frozen orange slices, lemon and lime or frozen berries,” said Nemeckay.

4. White Bread

Carbs are great for athletes and they help enhance their performance, but they tend to stay away from white bread. Everyday Health explains, white bread has little nutritional value, it boosts blood-sugar levels, increases risk of type-2 diabetes. It can also negatively impact your mood and cause weight gain. Athletes will get the majority of their carbs from leafy greens and whole grains.

5. Beer

According to Nemeckay, “Many athletes in a social sport like to finish off the game with a brewsky with their buds and although beer does have some carbs because it is alcohol it is a diuretic, which can lead to dehydration. If you must have a beer, drink plenty of water as well.”

6. Microwavable Popcorn

Microwavable popcorn is a huge no no for athletes. The artificial butter flavoring on the popcorn is poisonous to the body, there is harmful Perfluorooctanoic acid in the bag and it consists of toxic preservatives. However, it’s hard to imagine a movie without any popcorn; if an athlete really wants to satisfy their craving, they can air pop it on the stove and use a slight bit of coconut oil.

7. Sugary Sports Drinks

Shutterstock

“Many people think they need to “replace” their calories right after a workout. Sugary sports drinks increase the body’s production of insulin,” says Nemeckay.

8. Pasta

Athletes tend to stay away from pasta because it can increase their blood sugar levels. Although carbs are essential for energy, too much can be detrimental to their bodies. According to Jonny Bowden, PhD, CNS, “Consuming carbohydrates with a high glycemic index increases the risk of coronary heart disease in women, according to a new study in the Archives of Internal Medicine.” Tip: Eat quinoa or whole-wheat pasta

9. Pretzels

Although pretzels may seem like a great snack, 10 pretzels have 250 calories and a lot of salt. They are high in sodium and lack the necessary fiber and proteinan athlete needs in their diet. Pretzels lack nutritional value; they have almost no vitamins or nutrients that are good for you.

10. Fried Foods

Athletes would never eat fried foods -- especially before a workout. Fried foods take a long time to digest making their workout extremely uncomfortable and unproductive. Fried foods can also clog arteries and veins which can lead to strokes, heart attacks and aneurysms.

11. Cereal

Athletes never skip breakfast, but they lay off the sugary cereals. According to Liguori, cereal is one of the worst foods because of its lack of nutrients and protein. The sugar content is enormous and the amount of cereal you can fit in a bowl is usually way more than the serving size. This leading to an unproductive day due to an over indulgence of sugar. Instead athletes will eat eggs, smoothies and oatmeal for breakfast.

12. Flavored Yogurt

Shutterstock

“Yes, yogurt is protein, and it is good for building muscles, but it is the 20+ grams of sugar in the bottom that every athlete needs to avoid. Instead buy plain yogurt, and add fresh berries and nuts maybe a little honey,” said Nemeckay.

13. Coffee

Athletes like to reap the benefits of caffeine, but they tend to stay away from coffee and drink green tea instead. Coffee can cause heartburn and if you drink too much it can cause stress. “Drinking lots of coffee will promote the release of the stress hormones cortisol, epinephrine and norepinephrine. These chemicals increase your body’s heart rate, blood pressure and tension levels – the old ‘fight or flight’ response (Health Ambition).” It can also increase your LDL cholesterol levels, blood pressure and cause dehydration.

14. Energy Drinks

Athletes never use energy drinks to amp up their workouts. Energy drinks are extremely high in sugar; they can cause anxiety, headaches and rapid heart rate. These sugary drinks cause dehydration which could be detrimental to their training. Dehydration can cause them to experience muscle cramps, dizziness and fatigue. Athletes usually stick to water before, during and after their workout. Water keeps up their performance by keeping them energized and regulating their body temperature.

15. Artificial Sweeteners

Athletes tend to stay far away from artificial sweeteners. They cause a huge risk to metabolic heath and can cause health problems, mess with their hormones, overeating and weight gain. Two of the most dangerous artificial sweeteners include sucralose and aspartame.